ESP32 connection to Google cloud, Error : Settings incorrect or missing a cyper for SSL Connect with mqtt.2030.ltsapis.goog:8883 - google-cloud-platform

Question

i am trying to connect ESP32 with google cloude
but i am getting this error
Settings incorrect or missing a cyper for SSL
Connect with mqtt.2030.ltsapis.goog:8883
ClientId: projects/nomadic-armor-279716/locations/asia-east1/registries/iot-sample-registry/devices/esp32newD
Waiting 60 seconds, retry will likely fail
my code is divided over 4 files :
esp32main :
#include "esp32-mqtt.h"
void setup() {
// put your setup code here, to run once:
Serial.begin(115200);
pinMode(LED_BUILTIN, OUTPUT);
setupCloudIoT();
}
void loop() {
mqttClient->loop();
delay(10); // <- fixes some issues with WiFi stability
if (!mqttClient->connected()) {
connect();
}
}
ciotic_config.h
// This file contains your configuration used to connect to Cloud IoT Core
#include "credentials.h"
// Wifi newtork details.
const char *ssid = WIFI_SSID;
const char *password = WIFI_PASSWD;
// Cloud iot details.
const char *project_id = PROJECT_ID;
const char *location = REGION;
const char *registry_id = REGISTRY;
const char *device_id = DEVICE;
// Configuration for NTP
const char* ntp_primary = "pool.ntp.org";
const char* ntp_secondary = "time.nist.gov";
#ifndef LED_BUILTIN
#define LED_BUILTIN 5
#endif
// To get the private key run (where private-key.pem is the ec private key
// used to create the certificate uploaded to google cloud iot):
// openssl ec -in <private-key.pem> -noout -text
// and copy priv: part.
// The key length should be exactly the same as the key length bellow (32 pairs
// of hex digits). If it's bigger and it starts with "00:" delete the "00:". If
// it's smaller add "00:" to the start. If it's too big or too small something
// is probably wrong with your key.
const char *private_key_str =
// Replace this below string with your own, in the same format
// The below key is dummy, so using it will not help you in any way
"f3:36:fe:81:72:36:77:60:29:1d:4a:fc:21:c7:6c:"
"96:75:2c:7f:6e:52:2f:c8:cb:7d:03:c8:25:ef:28:"
"61:0b";
// Time (seconds) to expire token += 20 minutes for drift
const int jwt_exp_secs = 3600; // Maximum 24H (3600*24)
// To get the certificate for your region run:
// openssl s_client -showcerts -connect mqtt.googleapis.com:8883
// for standard mqtt or for LTS:
// openssl s_client -showcerts -connect mqtt.2030.ltsapis.goog:8883
// Copy the certificate (all lines between and including ---BEGIN CERTIFICATE---
// and --END CERTIFICATE--) to root.cert and put here on the root_cert variable.
const char *root_cert =
"-----BEGIN CERTIFICATE-----\n"
"MIIDfDCCAmSgAwIBAgIJAJB2iRjpM5OgMA0GCSqGSIb3DQEBCwUAME4xMTAvBgNV\n"
"BAsMKE5vIFNOSSBwcm92aWRlZDsgcGxlYXNlIGZpeCB5b3VyIGNsaWVudC4xGTAX\n"
"BgNVBAMTEGludmFsaWQyLmludmFsaWQwHhcNMTUwMTAxMDAwMDAwWhcNMzAwMTAx\n"
"MDAwMDAwWjBOMTEwLwYDVQQLDChObyBTTkkgcHJvdmlkZWQ7IHBsZWFzZSBmaXgg\n"
"eW91ciBjbGllbnQuMRkwFwYDVQQDExBpbnZhbGlkMi5pbnZhbGlkMIIBIjANBgkq\n"
"hkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAzWJP5cMThJgMBeTvRKKl7N6ZcZAbKDVA\n"
"tNBNnRhIgSitXxCzKtt9rp2RHkLn76oZjdNO25EPp+QgMiWU/rkkB00Y18Oahw5f\n"
"i8s+K9dRv6i+gSOiv2jlIeW/S0hOswUUDH0JXFkEPKILzpl5ML7wdp5kt93vHxa7\n"
"HswOtAxEz2WtxMdezm/3CgO3sls20wl3W03iI+kCt7HyvhGy2aRPLhJfeABpQr0U\n"
"ku3q6mtomy2cgFawekN/X/aH8KknX799MPcuWutM2q88mtUEBsuZmy2nsjK9J7/y\n"
"hhCRDzOV/yY8c5+l/u/rWuwwkZ2lgzGp4xBBfhXdr6+m9kmwWCUm9QIDAQABo10w\n"
"WzAOBgNVHQ8BAf8EBAMCAqQwHQYDVR0lBBYwFAYIKwYBBQUHAwEGCCsGAQUFBwMC\n"
"MA8GA1UdEwEB/wQFMAMBAf8wGQYDVR0OBBIEELsPOJZvPr5PK0bQQWrUrLUwDQYJ\n"
"KoZIhvcNAQELBQADggEBALnZ4lRc9WHtafO4Y+0DWp4qgSdaGygzS/wtcRP+S2V+\n"
"HFOCeYDmeZ9qs0WpNlrtyeBKzBH8hOt9y8aUbZBw2M1F2Mi23Q+dhAEUfQCOKbIT\n"
"tunBuVfDTTbAHUuNl/eyr78v8Egi133z7zVgydVG1KA0AOSCB+B65glbpx+xMCpg\n"
"ZLux9THydwg3tPo/LfYbRCof+Mb8I3ZCY9O6FfZGjuxJn+0ux3SDora3NX/FmJ+i\n"
"kTCTsMtIFWhH3hoyYAamOOuITpPZHD7yP0lfbuncGDEqAQu2YWbYxRixfq2VSxgv\n"
"gWbFcmkgBLYpE8iDWT3Kdluo1+6PHaDaLg2SacOY6Go=\n"
"-----END CERTIFICATE-----\n";
// In case we ever need extra topics
const int ex_num_topics = 0;
const char* ex_topics[ex_num_topics];
//const int ex_num_topics = 1;
//const char* ex_topics[ex_num_topics] = {
// "/devices/my-device/tbd/#"
//};
credentials.h
#define WIFI_SSID "Taha"
#define WIFI_PASSWD "mkt193540"
#define PROJECT_ID "nomadic-armor-279716"
#define REGION "asia-east1"
#define REGISTRY "iot-sample-registry"
#define DEVICE "esp32newD"
esp32-mqtt.h
// This file contains static methods for API requests using Wifi / MQTT
#ifndef __ESP32_MQTT_H__
#define __ESP32_MQTT_H__
#include <Client.h>
#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <MQTT.h>
#include <CloudIoTCore.h>
#include <CloudIoTCoreMqtt.h>
#include "ciotc_config.h" // Update this file with your configuration
// The MQTT callback function for commands and configuration updates
// Place your message handler code here.
void messageReceived(String &topic, String &payload) {
Serial.println("incoming: " + topic + " - " + payload);
int ledonpos=payload.indexOf("ledon");
if (ledonpos != -1) {
// If yes, switch ON the ESP32 internal led
Serial.println("Switch led on");
digitalWrite(LED_BUILTIN, HIGH);
} else {
// If no, switch off the ESP32 internal led
Serial.println("Switch led off");
digitalWrite(LED_BUILTIN, LOW);
}
}
/////////////////////////////////////////////
// Initialize WiFi and MQTT for this board //
Client *netClient;
CloudIoTCoreDevice *device;
CloudIoTCoreMqtt *mqtt;
MQTTClient *mqttClient;
unsigned long iss = 0;
String jwt;
/*
///////////////////////////////
// Helpers specific to this board
///////////////////////////////
String getDefaultSensor() {
return "Wifi: " + String(WiFi.RSSI()) + "db";
}
*/
String getJwt() {
iss = time(nullptr);
Serial.println("Refreshing JWT");
jwt = device->createJWT(iss, jwt_exp_secs);
return jwt;
}
void setupWifi() {
Serial.println("Starting wifi");
WiFi.mode(WIFI_STA);
// WiFi.setSleep(false); // May help with disconnect? Seems to have been removed from WiFi
WiFi.begin(ssid, password);
Serial.println("Connecting to WiFi");
while (WiFi.status() != WL_CONNECTED) {
delay(100);
}
configTime(0, 0, ntp_primary, ntp_secondary);
Serial.println("Waiting on time sync...");
while (time(nullptr) < 1592336214) {
delay(10);
}
}
void connectWifi() {
Serial.print("checking wifi...");
while (WiFi.status() != WL_CONNECTED) {
Serial.print(".");
delay(1000);
}
}
void connect() {
connectWifi();
mqtt->mqttConnect();
}
void setupCloudIoT() {
device = new CloudIoTCoreDevice(
project_id, location, registry_id, device_id,
private_key_str);
setupWifi();
netClient = new WiFiClientSecure();
mqttClient = new MQTTClient(512);//1024
mqttClient->setOptions(180, true, 1000); // keepAlive, cleanSession, timeout
mqtt = new CloudIoTCoreMqtt(mqttClient, netClient, device);
mqtt->setUseLts(true);
mqtt->startMQTT();
}
#endif //__ESP32_MQTT_H__
this code suppose to communicate with cloud and receive "ledon" or "ledoff" and implement the command.

Answer 1

First post in here. I was trying the same thing here and just got comm between my ESP8266 and GCP. I've learned three major things:
ESP32 and ESP8266 share a few libraries that are not compatible. You need to select the right one.
On root_cert you need to put the RSA_key
On private key (on firmware) you put the EC_private, while in the IoT Core you put the ec_public.
Good luck.